1. Field of the Invention
The invention relates to a magnetic sensor using a magnetoresistance effect element (a tunnel magnetoresistance (TMR) element or a giant magnetoresistance (GMR) element) and a magnetic balance type current sensor including the same.
2. Description of the Related Art
As a magnetic detection element used for a magnetic sensor, a magnetoresistance effect element, for example, a GMR element, has been used. The GMR element includes an antiferromagnetic layer, a fixed magnetic layer, a non-magnetic material layer, and a free magnetic layer as a basic film configuration. The fixed magnetic layer is formed to come into contact with the antiferromagnetic layer, and a magnetization direction is fixed in a single direction attributable to an exchange coupling magnetic field (Hex) generated between the fixed magnetic layer and the antiferromagnetic layer. Further, the free magnetic layer is laminated through the fixed magnetic layer and the non-magnetic material layer (non-magnetic layer). The magnetization of the free magnetic layer is not fixed and magnetized with respect to an external magnetic field. Further, electrical resistance varies due to the relationship between the magnetization direction of the free magnetic layer and the magnetization direction of the fixed magnetic layer. In such a magnetic sensor, in order to increase the linear relationship (linearity) between the resistance of the magnetoresistance effect element and the strength of the external magnetic field, a magnetic sensor in which hard bias layers are provided on the outside of the magnetoresistance effect element has been provided (Japanese Unexamined Patent Application Publication No. 2005-183614).
A magnetic sensor disclosed in Japanese Unexamined Patent Application Publication No. 2005-183614 includes a configuration in which the longitudinal directions of a plurality of stripe-shaped magnetoresistance effect elements are disposed such that the longitudinal directions of the magnetoresistance effect elements are parallel to each other, and in which a hard bias layer is provided on the ends of two adjacent stripe-shaped magnetoresistance effect elements. In the magnetic sensor, the hard bias layer is formed to serve as an electrode and to be laid on the ends of two adjacent stripe-shaped magnetoresistance effect elements.